Automobiles are typically provided with fuel canisters for reducing vapour emission from the fuel tank. This is often achieved using a carbon based monolith which is placed in line with the canister in order to adsorb vapours from the fuel tank. Such monoliths may be located remotely from the canister and connected via a pipe or may be installed in a suitable chamber integrated into the canister body.
In order to secure the monolith within the integrated chamber and to ensure that vapour flows through the monolith (rather than around it) it is typically sandwiched between a pair of rubber seal plugs. However, the material required for these seals to retain the monolith securely and to ensure a sufficient seal to the vapour, is relatively expensive. Furthermore, the monolith (which is typically manufactured from a brittle material) is easily damaged during insertion into the chamber.
Another problem with current monolith chamber arrangements is that, once in position, a resilient compensation system typically compresses the monolith arrangement from above. This can cause undesirable axial movement of the monolith within the chamber after manufacture of the fuel canister.